This invention relates to the locking of covers onto housings, in general, and to the locking of a cover on a swimming pool drain, in particular.
As will be appreciated, in recent months, there have been increasing reports in the media of children and adults alike being trapped in swimming pool drainsxe2x80x94sometimes with very tragic results.
In accordance with the present invention, analysis has revealed that these events have occurred primarily at swim clubs and at condominium swimming pools, rather than at pools at private residences. Further investigation, in accordance with the invention, has revealed that these unfortunate circumstances follow from the inadequacies of the cover for the swimming pool drainxe2x80x94whether the drain be located 6 feet or more below the surface of the water or at only some 12 inch or so below, as in a kiddie pool.
In particular, this investigation has shown that the problem, by and large, results from the typical manner of securing the cover to the drain. With most, if not all the manners of securement being by way of a pair of screws inserted through the plastic cover to fit with a pair of plastic sleeves in the drain housing, it will be easy to understand how the stepping on the cover at the bottom of the pool (for example, in the kiddie pool environment) is able to exert a sideways pressure on the screws in the sleeves, sufficient to break the plastic away freeing, or at the least, loosening the join with the drain. As will be appreciated, this reduces the protection of the cover from the workings of the pump connected to the drainxe2x80x94which is of a capacity to generate hundreds of pounds of suction.
Moreover, the very servicing of large size pools creates problems in-and-of themselves. Typically, swim club and condominium pools are serviced at season""s beginning or end, by pulling the cover from the drain and applying large pumps to drain the pool, before putting the cover back in place. On several occasions, the screws that held the cover in position beforehand simply are lost, and not replaced. In other instances, improperly sized screws are reinserted, breaking apart the plastic sleeves which previously held them. Where the serviceperson is aware of this and is conscientious, he, or she, often tries to correct the damage through an application of epoxy (but, that is really nothing more than a temporary fix). And, even at the very most, the repeated taking off, and putting the cover back on after service, has been noted to weaken the securement of the cover onto the drain over time. Because of the horrific consequences which can follow from leaving the drain unprotected, or in a weakened cover condition, a better, more secure drain cover would be highly desirable.
It is an object of the present invention, therefore, to provide a new and improved cover connection for a swimming pool drain of the type embedded in the concrete or liner of the swimming pool itself.
It is an object of the invention, also, to provide such a cover which can simply be exchanged for those already in use, in affording the increased protection which it is so important to have.
It is object of the present invention, in addition, to provide a cover of this type which can be easily afforded and installed as part of a yearly service call.
As will become clear from the following description, while the teachings of the present invention are particularly applicable in the context of this swimming pool protection scheme, the constructions described are equally attractive for use where any type of cover is to be secured to a housing. Thus, and as will be described, in accordance with the invention, a bridge is provided having downwardly extending upper arms and upwardly extending lower arms which are arranged to be drawn towards one another upon tighteningxe2x80x94and in a manner to bring two or more feet pivotally connected between their adjacent facing surfaces to bear against inside surfaces of the housing to be covered. Thus, in its preferred embodiment, two or more feet are pivotally connected between adjacent first ends of the downwardly extending upper arms and the upwardly extending lower arms of the bridge, with means being included to couple the bridge with the cover in enclosing the bridge within the housing upon which the cover is initially rested. In accordance with this preferred embodiment, second means then cooperate with the first means to rotate the upper and lower arms of the bridge in applying this bearing pressure of the feet against the inside surfaces of the housing in securing the cover in position.
In accordance with the invention, the bridge includes first and second hubs which receive opposing second ends of the downwardly extending upper arms and of the upwardly extending lower arms, respectively, in pivot connection with the first and second hubs. In this embodiment, the first and second means cooperate to rotate the upper extending arms downwardly and the downwardly extending arms upwardly when securing the cover in placexe2x80x94with the arms being equally spaced one from anotherxe2x80x94as, for example, with three such downwardly extending upper arms and three upwardly extending lower arms spaced at 120xc2x0 intervals one from another.
In effectuating the securement, the first means includes a bolt extending through the cover in joining with a threaded central core of the two hubs. In such respect, a cap on the bolt serves as the aforesaid second means in rotating the upper and lower arms of the bridgexe2x80x94and in a preferred embodiment of the invention, the bolt includes oppositely oriented threads on its upper and lower ends. Employing, then, a first thread, for example, along an upper substantially one-half length of the bolt and a second opposing thread along a lower substantially one-half length thereof, rotating the bolt in a clockwise direction serves to draw the upper and lower arms toward each other while rotating the bolt in a counterclockwise direction serves to deflect the arms away. In such manner, a serviceperson accessing the bolt by its cap passing through the cover can effectively lock the cover in position by utilizing a ratchet wrench, for example, to rotate the bolt, in bringing the feet up to exert pressure against the inside surfaces of the housing, in securing the cover in position.
In accordance with a preferred embodiment of the invention, the commonly employed plastic cover of xe2x80x9cdomexe2x80x9d configuration can be utilized, with a 6-8 inch diameter when employed on a swimming pool drain, with a peak of approximately 1 inch at its center. Through an aperture in such cover, the double-threaded bolt is arranged to pass in joining with the threaded cores of the hubs. In a preferred embodiment, a second bolt passes through a second aperture in the cover, to prevent the bridge from swinging about as it is ratcheted open or closed (as by turning the wrench or otherwise tightening or loosening the cap). Recessing the caps of the two bolts within the cover affords further protecting to a user of the pool when either stepping on or accidentally knocking into the cover, wherever it may be usedxe2x80x94in a kiddie pool, swimming pool, or elsewhere.
When employed particularly in a swimming pool environment, the housing serving as the drain with the invention can utilizexe2x80x94as it commonly doesxe2x80x94side and bottom outlet ports, with the first being threaded to receive a pipe conduit for coupling to the filtration system of the swimming pool, and with the latter being threaded to receive a removable plug for ground water release. As will be appreciated by those skilled in the art, however, the lockable cover in this manner can be used, as well, for any type of housingxe2x80x94and, not only for protecting against the heavy suction of swimming pool filtration equipment.